Robots have already revealed much about the mysterious Red Planet, which scientists believe was once wetter and warmer.

The British-led Beagle 2 lander and Nasa's own twin Mars Exploration Rovers, due to land on the planet in 2003, will hopefully reveal more.

But many believe that a human mission remains the only way to conclusively answer some of the key questions.

The fact is we're not safe and secure on our cradle of the Earth

Michael Foale

Dr Foale, whose parents still live in Cambridge, said: "It is more than an issue of just curiosity - it's a combination of instincts that human beings express about exploration and developing new territory.

"Some of it's not particularly attractive - it's to do with conquest or having more resources to use up. Others are more attractive because it's to do with learning and understanding more.

"The fact is we're not safe and secure on our cradle of the Earth.

Colin Pillinger designed the Beagle 2

"There are planetary bodies flying by on a regular basis. Asteroids have hit the Earth. So it is in our interests to explore.

"Ten years ago the plan was to spend 30 days on the surface of Mars. Now the accepted idea is to go and stay for more than a year.

"I think that is the way to go because then you start answering the serious questions. When and if life appeared on the Martian surface?

This is a time for Britain to seize the moment

Michael Foale

"Are there any fossil remains that can be detected? It allows you to do drilling, to do surveys, to do a full scientific programme.

"Also, you would learn a lot more about what happened to the climate on Mars. Why it is so dry now, when in the past it had a wet climate? A lot of those questions are thought to be understood, to some extent, but you need to go there to really explore."

Perilous journey

Sending astronauts to Mars and getting them back safely is no simple undertaking.

Their hazardous journey will be far more difficult to accomplish than the landing of three men on the Moon in 1969.

Mars has fascinated people for centuries

The Moon was only a short sprint compared to the 460-million-kilometre (286 million miles) voyage to Mars.

When they leave Earth, the astronauts will not be able to return for more than two and a half years.

The journey there will take between four and six months, depending on the propulsion system used.

After the crew arrives, they will have to remain on the Red Planet for more than a year until the proper alignment of Earth and Mars allows them to make the trip home.

Rocket fuel will have to be manufactured to get them back. Their bodies will be bombarded with radiation, their bone mass will decrease and they will have to deal with the loneliness of being apart from their families.

Missing his family is the hardest thing for Dr Foale

But Dr Foale knows all about the stresses of long-duration spaceflight and staying cool in a crisis.

In 1997, he spent 145 days aboard the old Russian space station Mir and narrowly escaped death when it was struck by a cargo ship.

"It weighed about seven tonnes so the impact was very noticeable. We heard a big thud and I remember having a severe adrenalin rush and thinking about how much longer do we have.

"I felt the fall of the air pressure in my ears and realised it was fairly severe but not so severe that we wouldn't have time to evacuate. It all started to fit together and a plan even started to form in all our minds that we would be ok - or we could be ok."

Mir disaster

Rather than put him off space travel for life, his Mir experiences just fired the Briton's passion for space travel even more.

He is due to lead a mission to the ISS in July 2003 and will spend 180 days in the station alongside cosmonaut Valery Tokarev and astronaut Bill McArthur.

Expedition 8, as they will be known, will be carrying out essential construction work, testing how parts of the body react to zero gravity and observing the Earth to help troubleshoot any pollution problems.

He was on Mir when it was hit by a cargo ship

"When you are away on a long mission, the main thing you miss obviously is your family, but you are always busy and communications are getting a lot better.

"I also really miss the fresh air. You can look down and see a beautiful blue Earth, but it is still through a window or the helmet of a spacesuit.

"You can actually see the wind blowing in the Southern Ocean. But you can't feel it and I do miss that feeling of wind on my face."

Dr Foale is also a strong believer that the UK Government should be doing more to encourage human space travel by funding a British-paid British astronaut in the International Space Station programme.

He said: "I don't count because I am paid for by the Americans."

Carrying out work on the Hubble Space Telescope

Other British astronauts like Piers Sellers and Helen Sharman have also had to look outside Britain to achieve their space ambitions.